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Information on EC 1.1.1.325 - sepiapterin reductase (L-threo-7,8-dihydrobiopterin-forming)
for references in articles please use BRENDA:EC1.1.1.325
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EC Tree 1 Oxidoreductases
1.1 Acting on the CH-OH group of donors
1.1.1 With NAD+ or NADP+ as acceptor
1.1.1.325 sepiapterin reductase (L-threo-7,8-dihydrobiopterin-forming)
IUBMB Comments
This enzyme, isolated from the bacterium Chlorobium tepidum, catalyses the final step in the de novo synthesis of tetrahydrobiopterin from GTP. cf. EC 1.1.1.153, sepiapterin reductase (L-erythro-7,8-dihydrobiopterin-forming).
The expected taxonomic range for this enzyme is: Bacteria, Eukaryota
Reaction Schemes
showSynonyms
MDSPR, sepiapterin reductase, SPR, more
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SYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
sepiapterin reductase
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REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
L-threo-7,8-dihydrobiopterin + NADP+ = sepiapterin + NADPH + H+
(1)
-
-
-
L-threo-tetrahydrobiopterin + 2 NADP+ = 6-pyruvoyl-5,6,7,8-tetrahydropterin + 2 NADPH + 2 H+
(2)
-
-
-
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PATHWAY SOURCE
PATHWAYS
KEGG
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SYSTEMATIC NAME
IUBMB Comments
L-threo-7,8-dihydrobiopterin:NADP+ oxidoreductase
This enzyme, isolated from the bacterium Chlorobium tepidum, catalyses the final step in the de novo synthesis of tetrahydrobiopterin from GTP. cf. EC 1.1.1.153, sepiapterin reductase (L-erythro-7,8-dihydrobiopterin-forming).
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SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
LITERATURE
COMMENTARY
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
6-pyruvoyl-5,6,7,8-tetrahydropterin + 3 NADPH + 3 H+
L-threo-7,8-dihydrobiopterin + 3 NADP+
-
Substrates: -
Products: -
Products: -
?
6-pyruvoyl-5,6,7,8-tetrahydropterin + NADPH + H+
L-threo-7,8-dihydrobiopterin + NADP+
-
Substrates: -
Products: -
Products: -
?
L-threo-7,8-dihydrobiopterin + NADP+
sepiapterin + NADPH + H+
-
Substrates: -
Products: -
Products: -
r
sepiapterin + NADPH + H+
L-threo-7,8-dihydrobiopterin + NADP+
Substrates: -
Products: -
Products: -
?
sepiapterin + NADPH + H+
tetrahydrobiopterin + NADP+
Substrates: -
Products: no stereochemic specification in the publication
Products: no stereochemic specification in the publication
?
additional information
?
-
-
Substrates: the enzyme also shows activity with D-threo-dihydrobiopterin, L-threo-dihydroneopterin, and dihydrotepidopterin, and low activity with L-erythro-dihydrobiopterin
Products: -
Products: -
?
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NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
LITERATURE
COMMENTARY
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
6-pyruvoyl-5,6,7,8-tetrahydropterin + 3 NADPH + 3 H+
L-threo-7,8-dihydrobiopterin + 3 NADP+
-
Substrates: -
Products: -
Products: -
?
6-pyruvoyl-5,6,7,8-tetrahydropterin + NADPH + H+
L-threo-7,8-dihydrobiopterin + NADP+
-
Substrates: -
Products: -
Products: -
?
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COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
additional information
-
N-acetylserotonin and melatonin are no inhibitors
-
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KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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pH RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
2.5 - 12
activity range, profile overview, recombinant His-tagged enzyme, over 50% of maximal activity at pH 3.0-11.0
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TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
50
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TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
20 - 90
activity range, profile overview, recombinant His-tagged enzyme, over 50% of maximal activity at 30-85°C
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ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
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SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
additional information
during the development of Musca domestica, the expression of MDSPR in the larvae is higher than other developmental stages
brenda
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LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
Highest Expressing Human Cell Lines
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GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
metabolism
sepiapterin reductase (SPR) catalyzes the final steps of tetrahydrobiopterin (BH4) biosynthesis
physiological function
sepiapterin reductase (SPR) catalyzes the final steps of tetrahydrobiopterin (BH4) biosynthesis. BH4 is an essential cofactor for aromatic acid hydroxylases and nitric oxide synthase. BH4 deficiency causes endothelial dysfunction, such as hypertension, atherosclerosis, diabetes, etc.
additional information
-
alignment of amino acid sequences near the N-termini of sepiapterin reductases from various sources, overview
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UNIPROT
ENTRY NAME
ORGANISM
NO. OF AA
NO. OF TRANSM. HELICES
MOLECULAR WEIGHT[Da]
SOURCE
SEQUENCE
LOCALIZATION PREDICTION
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable).
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable). SPRE_CHLTE
Chlorobaculum tepidum (strain ATCC 49652 / DSM 12025 / NBRC 103806 / TLS)
244
0
27114
Swiss-Prot
-
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MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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SUBUNIT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
?
x * 51000, SDS-PAGE, recombinant fusion protein, x * 31494, calculated
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CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
purified recombinant His-tagged wild-type and selenomethionine-substituted enzymes, hanging drop vapour diffusion method at 18°C, mixing of 0.004 ml of protein solution containing 10 mg/ml in 20 mM Tris-HCl, pH 8.0, by ultrafiltration, with 0.001 ml of reservoir solution containing 0.2 M MgCl2, 0.1 M Tris-HCl, pH 8.5, 34% PEG 400, and 0.2 M guanidine hydrochloride, screening and method optimization, crystals of the wild-type enzyme are soaked in reservoir solution containing 1 mM NADP+ and 1 mM sepiapterin or containing 1 mM NADP+ and 1 mM N-acetylserotonin, respectively, X-ray diffraction structure determination and analysis at 2.1 A resolution
-
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GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
stability of the purified enzyme disappears in sodium citrate buffer and potassium phosphate buffer for 24 h at 4°C, it increases continuously in Tris-HCl buffer and in glycine/NaOH buffer
-
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PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
native enzyme 533fold from cytosol by ammonium sulfate fractionation, anion exchange chromatography, and gel filtration followed by affinity chromatography, another different step of anion exchange chromatography, and ultrafiltration
-
recombinant His-tagged enzyme from Escherichia coli strain BL21(DE3)
recombinant His-tagged wild-type and selenomethionine-substituted enzymes from Escherichia coli strain BL21(DE3) by nickel affinity chromatography, ultrafiltration, anion exchange chromatography, and gel filtration
-
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CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
expression of His-tagged wild-type and selenomethionine-substituted enzymes in Escherichia coli strain BL21(DE3)
-
subtractive cDNA library screening, DNA and amino acid sequence determination and analysis, sequence comparisons, phylogenetic tree, recombinant expression of His-tagged enzyme in Escherichia coli strain BL21(DE3)
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EXPRESSION
ORGANISM
UNIPROT
LITERATURE
infection with Escherichia coli induces the enzyme in Musca domestica larvae, highest after 24 h
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REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Cho, S.H.; Na, J.U.; Youn, H.; Hwang, C.S.; Lee, C.H.; Kang, S.O.
Sepiapterin reductase producing L-threo-dihydrobiopterin from Chlorobium tepidum
Biochem. J.
340
497-503
1999
Chlorobaculum tepidum
-
brenda
Supangat, S.; Choi, Y.K.; Park, Y.S.; Son, D.; Han, C.D.; Lee, K.H.
Expression, purification, crystallization and preliminary X-ray analysis of sepiapterin reductase from Chlorobium tepidum
Acta Crystallogr. Sect. F
61
202-204
2005
Chlorobaculum tepidum
brenda
Tang, Y.; Pei, Z.; Liu, L.; Wang, D.; Kong, L.; Liu, S.; Jiang, X.; Gao, Y.; Ma, H.
Expression and enzyme activity detection of a sepiapterin reductase gene from Musca domestica larva
Appl. Biochem. Biotechnol.
181
604-612
2016
Musca domestica (A0A172EJV6)
brenda
EXTERNAL LINKS (specific for EC-Number 1.1.1.325)
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